Help came just in time for Michael Vann last Thursday, as temperatures lingered in the teens and the city braced for lows in the single digits the following morning.

Vann said the salt on the streets had melted the soles of his shoes. Only recently in New York, he and his girlfriend had been sleeping on the trains. Now at Grand Central Station, came a timely question: “What size sneaker do you wear?”

McDonnell, 40, started “It’s from the Sole” about three years ago. After working in the fashion industry for more than 15 years, McDonnell’s charitable epiphany came while playing basketball on a summer morning before work, when he spotted a homeless man walking across the street with no shoes.

McDonnell, who was born in Barbados and grew up in Brooklyn, said he offered the man a pair of new sneakers he had with him, and a pair of socks. He went to work, at the designer men’s clothing store Atrium, and the idea was born: collect sneakers and distribute them to homeless people living in New York.

In about an hour, he gave away about 11 pairs of new sneakers to homeless men and women in Grand Central.

Last year, McDonnell gave away 4,000 pair of sneakers by himself. The shoes are either donated by friends and supporters and cleaned by McDonnell, or given to him brand-new by companies. Two or three times a week, McDonnell packs a bag full of sneakers, and heads to Grand Central, Penn Station and other places where he knows homeless people congregate.

A few minutes after stepping off the 6 train, McDonnell spots a sleeping man wearing a faded and dirty pair of blue and gray Nike sneakers. McDonnell pulls up his Instagram and finds a photo of the man 22 weeks earlier, sitting on the same bench, receiving the pair of sneakers now on his feet.

McDonnell gently wakes up the man, asks him to remind him what size shoe he wears — 9.5 or 10 — and hands him a fresh pair of black and red sneakers.

He passes out another pair to Juan Vasquez, who was using a payphone near the central terminal to call in his unemployment.

Vasquez said he recently spent about three months in a city shelter before finding a basement to stay in the Bronx.

“The shelters are a mess, because you’ve got people there who don’t want to follow the plan, they want to sell cigarettes, smoke weed, like a club, and do all these nasty things,” Vasquez said. “But sometimes you have to choose the lesser of two evils. The shelter is not the safest, but if you’re sleeping on the trains you have no protection.”

Vasquez said he received winter clothes from a local church last year, but has never been offered a pair of brand new shoes before.

“There has to be more people willing to do that, the homeless situation is getting worse,” Vasquez said.

In about an hour, McDonnell gave away about 11 pairs of new sneakers to homeless men and women in Grand Central.

Before the afternoon is up, McDonnell will meet more than one person who is apprehensive, refuses his help out of pride, or thinks he’s trying to sell the sneakers in his bag, some of which are worth hundreds of dollars.

“It’s not easy, because you can’t tell them how to react towards you, you can’t tell them to chill out, not to scream, you can’t tell them not to yell. I’ve been yelled at, cursed out, spit at before,” McDonnell said. “But I can’t tell this guy who has no home how to behave.”

After receiving a good amount of media attention around the holidays, McDonnell is working to make It’s From the Sole a 501(c) 3 organization this year, which he says will mean more donations from companies. He also wants to get high school and college students involved, and bridge the gap between the homeless and the rest of New York.

“A lot of people want to help the homeless but don’t want to deal with them,” McDonnell said. “I’m going to help you help them.”

By the numbers:

58,284: Number of New Yorkers who spent February 18 in a homeless shelter

54,321: Number of New Yorkers who spent February 2014 in a homeless shelter

50,996: Number of New Yorkers who spent February 2013 in a homeless shelter

(Numbers from the New York City Department of Homeless Services and Coalition for the Homeless)